THE INFLUENCE OF INCORPORATED RADIOACTIVITY AND EXTERNAL RADIATION ON THE DEHYDRATION OF CYCLOHEXANOL OVER SULFATE CATALYSTS

Thesis/Dissertation · Mon Jan 01 00:00:00 EST 1962

OSTI ID:4757696

Krohn, N A

The vapor phase dehydration of cyclohexanol on magnesium sulfate and magnesium suifate --sodium sulfate catalysts was studied. The effects of the incorporation of radioactive S into the sulfate radical, x irradiation of the catalyst while in use, and preirradiation with gamma rays were investigated. It was concluded that the reported enhancements of catalytic activity by the addition of radioactive S are erroneous. When compared on a unit surface area basis, the radioactive catalysts were found to be less active than nonradioactive catalysts of the same composition. The erroneous reports may be attributed to the fact that for a given heat treatment, the radioactive catalysts have larger surface areas than their nonradioactive counterparts. The crystallite size of the radioactive materials appears to be smaller for a given heat treatment. It was also determined that both the nonradioactive and radioactive materials lose catalytic activity with storage time and that, therefore, this phenomenon is not related to the decay of the radioactivity, but is a property of the catalyst surface. From this it was concluded that the emission of beta particles from the catalyst during the time the dehydration reaction was taking place was of no consequence. This conclusion was supported by the fact that irradiation of the catalysts with x rays or electrons while the reaction was proceeding had no effect. Preirradiation of the catalyst with Co/sup 60/ gamma rays was also shown to have no significant effect. Other conclusions are that the reaction is first order with respect to the partial pressure of cyclohexanol and that it may be limited in extent by the attainment of equilibrium. The products, regardless of the catalyst used or its radioactivity, were limited to cyclohexene and water. It is also concluded that water, while it may play a part in the aging processes, does not strongly poison the catalyst at temperatures above 350 deg . Average values for the apparent activation energies found were about 24 and 28 kcal/mole for fresh and aged magnesium sulfate and 23 and 29 kcal/mole for fresh and aged magnesium sulfate containing 0.98 to 2.43% sodium. Considerable variation was found in the latter case. (P.C.H.)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-17-012742
• OSTI ID: 4757696
• Resource Relation: Other Information: Thesis. Orig. Receipt Date: 31-DEC-63
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

METALS, CERAMICS, AND OTHER MATERIALS
ACTIVATION
ALCOHOLS
BETA PARTICLES
CATALYSIS
COBALT 60
CRYSTALS
CYCLOALKANES
DECAY
ELECTRON BEAMS
EMISSION
ENERGY
GAMMA RADIATION
GRAIN SIZE
HEAT TREATMENTS
HEXANE
HYDRIDES
IRRADIATION
MAGNESIUM SULFATES
POISONING
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATION SOURCES
RADIOACTIVITY
REACTION KINETICS
SODIUM SULFATES
STORAGE
SULFATES
SULFUR
SURFACES
TEMPERATURE
VAPORS
VARIATIONS
WATER
X RADIATION